In general, a silicon single crystal ingot in a silicon single crystal ingot growing apparatus is produced to be grown by dipping a seed, by using a pulling apparatus, into a silicon melt formed by melting polysilicon and a dopant in a quartz crucible, and rotating the seed and the quartz crucible in opposite direction while slowly pulling up the seed.
The silicon single crystal ingot growing apparatus is formed to include a quartz crucible in which a silicon melt is filled in a hot zone (H/Z) of an inside of a chamber, a graphite crucible for surrounding the quartz crucible, a support plate for supporting the crucible, a rotation shaft for coupling the support plate to an external rotation driving apparatus, a heater installed in a structure surrounding the crucible to radiate heat to the crucible, and a heat shielding member for preventing heat generated from the heater from radiating to the outside and lowering the temperature of the silicon melt.
A seed chuck is provided in the chamber. The seed chuck dips a seed connected to an external pulling up driving apparatus such as a drum with a cable into the silicon melt and then pulls up the seed at a predetermined speed, and supports the load of the silicon single crystal ingot which is growing at one end of the seed.
When the silicon ingot is grown by the Czochralski method as described above, the cable is connected to one end of the seed, and the ingot is grown by the rotation driving, so that the seed portion is particularly shaken.
FIG. 1 is a graph illustrating a diameter according to a growth length of a conventional single crystal ingot.
Referring to FIG. 1, a result of measuring the diameter of the grown silicon ingot by length is illustrated, wherein a deviation of the diameter of the silicon ingot in a region A which is the beginning of the ingot growth is larger than in a region B, and a change period also illustrates that the region A is shorter than the region B.
As described above, the shaking of the seed occurs due to the rapid increase of the pulling speed or the light weight of the initial ingot at the beginning of growing of the single crystal ingot, and this causes a diameter deviation of the grown ingot, which causes a problem in which the usable area of the grown single crystal is reduced.